Proprietary software

Copyleft licenses are deliberately incompatible with proprietary licenses, in order to prevent copyleft software from being re-licensed under a proprietary license, turning it into proprietary software.

Proprietary software, also known as closed-source software, is a non-free computer software for which the software's publisher or another person retains intellectual property rights—usually copyright of the source code, but sometimes patent rights.

Free software is generally available at no cost and can result in permanently lower TCO costs compared to proprietary software.

It is a weak copyleft license, characterized as a middle ground between permissive free software licenses and the GNU General Public License (GPL), that seeks to balance the concerns of proprietary and open source developers.

The MIT license also permits reuse within proprietary software, provided that either all copies of the licensed software include a copy of the MIT License terms and the copyright notice, or the software is re-licensed to remove this requirement.

Software under the GPL may be run for all purposes, including commercial purposes and even as a tool for creating proprietary software, such as when using GPL-licensed compilers.

Most of the software is covered by copyright which, along with contract law, patents, and trade secrets, provides legal basis for its owner to establish exclusive rights.

Software copyright is used by Software Developers and proprietary software companies to prevent the unauthorized copying of their software.

Occasionally, software is made available with fewer restrictions on licensing or source-code access; such software is known as "free" or "open-source."

As a result, BSD code can be used in proprietary software that only acknowledges the authors.

Restricted use is sometimes enforced through a technical measure, such as product activation, a product key or serial number, a hardware key, or copy protection.

Product activation is a license validation procedure required by some proprietary computer software programs.

A software vendor delineates the specific terms of use in an end-user license agreement (EULA).

A free software license grants users of that software the rights to use for any purpose, modify and redistribute creative works and software, both of which are forbidden by the defaults of copyright, and generally not granted with proprietary software.

Proprietary software, also known as closed-source software, is a non-free computer software for which the software's publisher or another person retains intellectual property rights—usually copyright of the source code, but sometimes patent rights.

Software, and its accompanying source code, can be associated with several licensing paradigms; the most important distinction is open source vs proprietary software.

The Reference Source License (Ms-RSL) and Limited Public License (Ms-LPL) are proprietary software licenses where the source code is made available.

It is possible for a software to be both source available software and proprietary software.

Shareware is closed-source software whose owner encourages redistribution at no cost, but which the user sometimes must pay to use after a trial period.

Shareware is a type of proprietary software which is initially provided free of charge to users, who are allowed and encouraged to make and share copies of the program.

For example, the bytecode for programs written in Java can be easily decompiled to somewhat usable code, and the source code for programs written in scripting languages such as PHP or JavaScript is available at run time. Examples of proprietary software include Microsoft Windows, Adobe Flash Player, PS3 OS, iTunes, Adobe Photoshop, Google Earth, macOS (formerly Mac OS X and OS X), Skype, WinRAR, Oracle's version of Java and some versions of Unix.

The original and reference implementation Java compilers, virtual machines, and class libraries were originally released by Sun under proprietary licenses.

Apple has such a licensing model for macOS, an operating system which is limited to Apple hardware, both by licensing and various design decisions. Examples of proprietary software include Microsoft Windows, Adobe Flash Player, PS3 OS, iTunes, Adobe Photoshop, Google Earth, macOS (formerly Mac OS X and OS X), Skype, WinRAR, Oracle's version of Java and some versions of Unix.

macOS (previously Mac OS X and later OS X) is a series of non-free graphical operating systems developed and marketed by Apple Inc. since 2001.

According to documents released by Edward Snowden, the NSA has used covert partnerships with software companies to make commercial encryption software exploitable to eavesdropping, or to insert backdoors.

Although the number of backdoors in systems using proprietary software (software whose source code is not publicly available) is not widely credited, they are nevertheless frequently exposed.

The text-based email client Pine and certain implementations of Secure Shell are distributed with proprietary licenses that make the source code available.

Proprietary, freeware and open source (e.g. PuTTY, and the version of OpenSSH which is part of Cygwin ) versions of various levels of complexity and completeness exist.

Sometimes another vendor or a software's community themselves can provide support for the software, or the users can migrate to either competing systems with longer support life cycles or to FOSS-based systems.

This is in contrast to proprietary software, where the software is under restrictive copyright licensing and the source code is usually hidden from the users.

More examples of formerly closed-source software in the List of commercial software with available source code and List of commercial video games with available source code.

Commercial video games are typically developed as proprietary closed source software products, with the source code treated as a trade secret (unlike open-source video games).

Some of those kinds are free-of-charge downloads (freeware), some are still commercially sold (e.g. Arx Fatalis).

Freeware is software, most often proprietary, that is distributed at no monetary cost to the end user.

In 1983, binary software became copyrightable in the United States as well by the Apple vs. Franklin law decision, before which only source code was copyrightable.

Another impact of the decision was the rise of the shrink-wrap proprietary software commercial business model, where before a source code driven software distribution schema dominated.

More examples of formerly closed-source software in the List of commercial software with available source code and List of commercial video games with available source code.

For specifically formerly proprietary software which is now free software, see List of formerly proprietary software.

Sometimes for commercialization reasons, sometimes as security or anti-cheat measurement (Security through obscurity).

The underlying objective of these business models is to harness the size and international scope of the open-source community (typically more than an order of magnitude larger than what would be achieved with closed-source software equivalents) for a sustainable commercial venture.

Examples of proprietary software include Microsoft Windows, Adobe Flash Player, PS3 OS, iTunes, Adobe Photoshop, Google Earth, macOS (formerly Mac OS X and OS X), Skype, WinRAR, Oracle's version of Java and some versions of Unix.

Microsoft Windows, commonly referred to as Windows, is a group of several non-free graphical operating system families, all of which are developed, marketed and sold by Microsoft.

Proprietary software is not synonymous with commercial software, although the two terms are sometimes used synonymously in articles about free software.

Commercial software can be proprietary software or free and open-source software.

Occasionally, software is made available with fewer restrictions on licensing or source-code access; such software is known as "free" or "open-source."